U.S. Pat. No. 4,519,360 is related to the area of the electronic control of an internal combustion engine of a motor vehicle and discloses a throttle flap in the intake pipe system of the engine which is actuated by an actuator responding to an electrical control signal. The control signal is derived from the position of the accelerator pedal. Potentiometers connected to the accelerator pedal and the throttle flap supply a desired value signal and an actual value feedback signal. The actuating signals for the actuator are obtained from a comparison of these signals.
The throttle flap is biased by a spring in the direction toward its idle position or a pregiven closed position for reasons of safety. For this reason, each function interruption of the actuator during normal operation of the engine leads to a movement of the throttle flap in the direction of its idle position or closed position during the normal operation of the engine. This causes the output power of the engine to be reduced. It is the driver's direct reaction to depress the accelerator pedal when noticing this loss in power. The interruption can be of a short duration such as in the case of a loose contact in the electrical circuit of the actuator. If this is the case, then the actuator directs the throttle flap quickly into a new position as soon as it is again functional with this new position corresponding to the new position of the accelerator pedal. In this way, an undesired increase of the engine output power occurs greater than the one originally wanted by the driver. This can be a source of danger since the driver is not prepared for an increase in the engine output power especially if the driver is surprised thereby.